Recruiting is the lifeline of college coaches. And with teenagers using social media like Twitter to communicate, some football staffs have pushed the boundaries of NCAA regulations to reach top high school recruits.

National Signing Day is today and the stakes are high.

The NCAA allows schools to confirm they’re recruiting a specific unsigned prospect, but coaches can’t comment on that recruit’s athletic ability, how he’d contribute to their team or the likelihood that prospect might commit to a particular school.

Some coaches and staffers are bending the rules, tweeting thinly veiled references to prospects without naming them.

J.R. Sandlin was working as a recruiting analyst at Notre Dame on Dec. 17 when he tweeted, “The DT from KY calling me out. Just wait my man! Just wait! We want you here! Need u to be Irish!”

One day later, Sandlin tweeted that “what I like about ‘THE’ 2014 DT from KY is the explosive power he can generate from his lower body. Truly impressive. The guy is a BEAST!”

He didn’t name a prospect, but the only defensive tackle from Kentucky being recruited by Notre Dame was Matt Elam of John Hardin High in Elizabethtown.

The Twitter feed of five-star running back prospect Leonard Fournette of St. Augustine High in New Orleans is filled with references to “Buga Nation.” Fournette was still uncommitted on Dec. 18 when LSU coach Les Miles tweeted “Geaux Buga Nation!!!” Miles’ message received 782 retweets, including one from Fournette himself. Two weeks later, Fournette committed to LSU.

NCAA spokeswoman Stacey Osburn said the NCAA rules on what a coach says to or about a recruit also apply to social media.

“It doesn’t matter if you’re doing it when you talk to a reporter or are on social media,” Osburn said. “It’s the same rule.”

Jen Vining-Smith, Notre Dame’s assistant athletic director for compliance, said she got several calls from compliance officers at other universities regarding Sandlin’s Dec. 18 tweet about the Kentucky prospect. Vining-Smith told Sandlin she could defend the tweet, but she didn’t want him tweeting so “pointedly” again.

“I do think it pushes right up to the line. ... You can’t make it that identifiable,” Vining-Smith said.

Miles was reminded by LSU administration officials to use caution when taking to Twitter to discuss recruiting. He was not admonished, however, because officials determined that Miles had tweeted a phrase which was not a direct reference to Fournette, as opposed to using a publicly known nickname, for example.

Coaches can tweet to their heart’s content to let fans know that “someone” has verbally committed to their school without actually mentioning the recruit by name. And they’re doing it all over the country, whether it’s Tennessee’s Butch Jones tweeting “#BrickByBrick” or Texas A&M’s Kevin Sumlin tweeting “#Yessir!”

Some coaches, like Alabama’s Nick Saban, don’t use Twitter as a part of their recruiting tactics. But not everyone can afford to take the approach of Saban, who consistently lands top recruits.